In FileMaker GO, if you ask for Apple Maps to open with a tap on a valid address link, it does it perfectly. The Maps app opens in the foreground with FM-GO becoming the last visited app.
However, if you then tap the FileMaker Go button in the upper left corner of the screen, you see the "Reconnecting" screen momentarily and then you see a screen with the title "Opening Failure". The text in the screen says: "Failed to open:" followed by the URL that was used for the presentation of the map.
If you notice that there is a DONE button in the lower right corner and an "Open in Safari" link in the lower left corner, you can use either of them to dismiss the error and then it returns to FileMaker Go.
If there is a way to tell iOS to go back to FileMaker Go without hitting that error page, I don't know what it may be.